Modeling Phase Selection And Extended Solubility In Rapid Solidified Alloys

A new phase selection model based on the time-dependent nucleation theory was developed to investigate the effect of rapid solidification on extended solubility. The model was applied to predict the solubility as a function of undercooling for several binary Al alloys. The predictions of both eutectic and peritectic systems show good agreement with experimental data. It was demonstrated that the developed model is better than the T 0-line method, which neglected the kinetic process of nucleation. Furthermore, the model can also be applied to ternary and multicomponent phases assuming the nucleation is limited by the scarcest species or the slowest diffuser. The feasibility and reliability of the new model make it a useful tool for novel alloy design for rapid solidification processes such as additive manufacturing

Correction: Modeling Phase Selection And Extended Solubility In Rapid Solidified Alloys (Metallurgical And Materials Transactions A, (2023), 10.1007/s11661-023-07221-7)

In the original online version of this article the reference citation in Fig. 3b was incorrect. The original article was corrected

“Asymptomatic” plasmodium falciparum parasitemia and micronutrient deficiencies among pregnant women in Oyo State

Background: Plasmodium falciparum parasitemia coupled with nutritional deficiencies, especially relating to micronutrients in pregnancy, may be a recipe for adverse pregnancy outcomes. This study was conducted to determine the prevalence of asymptomatic P. falciparum infection and some micronutrient deficiencies among pregnant women in Oyo State. Methods: Three hundred and sixteen pregnant women aged 16–45 years and 100 apparently healthy nonpregnant women of the same age range serving as controls from the 3 senatorial districts of Oyo State were enrolled in this study after obtaining their consent. Blood samples were collected and examined for P. falciparum using RDT kit and Giemsa-stained film microscopy while the selected micronutrients – calcium, iron, copper, and zinc – were assayed with atomic absorption spectrophotometer. Results: P. falciparum was detected in 82 out of the 316 pregnant women studied representing a percentage prevalence of 25.95 while the prevalence rate was 1% (1 out of 100) among the nonpregnant control women (P < 0.0001). Factors that significantly impacted on P. falciparum prevalence were pregnancy status, age, gestational age, parity, and seasonal variations. Out of the 316 pregnant women studied, 27 (8.5%) and 35 (11.1%) were deficient in calcium and iron, respectively. However, 13 of the 82 parasitemic pregnant women (15.85%) had calcium micronutrient deficiency, with only 14 out 234 (5.98%) observed in nonparasitemic pregnant women (P < 0.0001). While 10 (12.19%) had iron deficiency among the parasitemic pregnant women, 25 (10.68%) had iron deficiency among the nonparasitemic pregnant women. The only parasitemic nonpregnant control out of the 100 had calcium and iron micronutrient deficiencies (100%) as against 24.24% and 20.24%, respectively, in nonparasitemic controls. Copper and zinc micronutrient deficiencies were not observed among the study subjects. Conclusion: Continuous health education with emphasis on compliance to dietary instructions and malaria prevention measures, monitoring parasitemic pregnant women till delivery, and including malaria testing in the routine laboratory tests for antenatal care are hereby advocated

Characterization of markers of chloroquine resistance in plasmodium falciparum among pregnant women in Oyo State: Any hope of chloroquine resistance reversal?

Background: Chloroquine (CQ) which is one of the 4-aminoquinolines was once the mainstay of malaria treatment before it was officially withdrawn due to widespread resistance to it by Plasmodium species. It is one of the cheapest, safest, easily produced antimalarial compounds and has one of the longest half-lives among the antimalarial drugs which are also safe for use in pregnancy. Reversal of CQ resistance back to sensitivity has been documented after a period of withdrawal, and this may be a great relief in achievement of effective antimalarial chemotherapy at a relatively cheaper cost in Nigeria. This study investigated the characterization of markers of CQ resistance in Plasmodium falciparum infection among pregnant women in Oyo State following several years of official CQ withdrawal for treatment in Nigeria. Materials and Methods: Thick and thin blood films were made from venous blood collected from 316 consenting pregnant women and dispensed into ethylenediaminetetraacetic acid bottles after initial screening with SD Bioline RDT kit. The blood films were processed for malaria microscopy using 10% Giemsa stain. Dry blood spots on Whatman no. 1 filter paper were used for parasite DNA extraction and subsequent detection of CQ resistance markers using restriction fragment length polymorphism. Results: Eighty-two out of the 316 samples were positive for P. falciparum and subjected to molecular analysis for the detection of Pfcrt and Pfmdr1 mutant genes. Out of the 82 positive cases, 75 and 80 expressed mutant Pfcrt and Pfmdr1 genes, respectively, while 73 expressed both Pfcrt and Pfmdr1 genes. Conclusion: The high prevalence of the two major molecular markers of CQ resistance in this study, portends a concern in achieving resurgence of sensitivity after years of official withdrawal, thus official malaria management protocols should be strictly adhered to by ensuring testing before drug use while also avoiding self-medication